Re: Backup Restore (Was: Re: Getting started with Tarsnap)

[Scott Wheeler <scott@directededge.com>]

On Feb 13, 2014, at 6:19 PM, Daniel Staal <DStaal@usa.net> wrote:

> Tarsnap is *online* backups - it has to download the data to do a restore. The problem could be your connection, the server, something upstream, etc. It's possible there's a problem Colin can/should fix, but that can't be determined from your posting.  We need to know exactly what you are seeing.

This is definitely a Tarsnap issue.  Restores are extremely slow.  I usually see around 1.5 Mbit/s on a 100 Mbit connection, which jives with what Vijay reported (~1.3 Mbit/s).  I brought this up with Colin a couple years ago and he said that it’s an issue of “a lack of pipelining in Tarsnap’s archive reading”.  You can however run multiple extractions in parallel.

This remains my biggest pain point with Tarsnap — it would still take us an unseemly amount of time to restore our customer data set (~35 GB — which would take approximately 53 hours to restore without split up the restores) in a disaster scenario.  As such we currently have a snapshot that gets overwritten daily and Tarsnap for the sequential daily backups, but this issue remains the reason that I can’t recommend Tarsnap to others as a viable primary backup tool.

-Scott